Active vibration control - A new approach to build extremely light bridges

This paper presents a new approach to build extremely light bridges. By using high-strength carbon fibre reinforced plastic (CFRP), a very light and flexible stress ribbon footbridge was built in the lab of the Chair of Conceptual and Structural Design at TU Berlin. It has a span of 13 m and a struc- tural height of only 1 mm. To reduce their exceptional high vibration sensitivity, an active vibration control concept was developed and applied to the prototype. This concept includes the embedding of smart actuators at handrail level. Here, biologically inspired, extremely light and powerful pneu- matic muscle actuators are used. The efficiency of the multimodal active vibration control is shown by an enormous reduction of pedestrian-induced accelerations in the first three vertical modes.

Finally, the findings show that active controlled lightweight structures are one step closer to the vision of “zero” structural height and “infinite” stiffness.